1. Field of the Invention
The present invention relates to a method of forming a plurality of bump electrodes en bloc on a bump electrode formation surface of a wafer from which chips are to be separated, or on a bump electrode formation surface on an upper surface side of a plurality of chips which are separated from a wafer and placed side by side, specifically for use in condenser chips, resistance chips, IC chips, and CPU chips, which are mounted on a surface of electronic parts, and for use in packages semi-conductor-molded ball grid arrays (BGA) and chip size packages (CSP) and connectors.
2. Discussion of Background
In accordance with a recent trend of down-sizing and cost reduction of electronic parts, the above-mentioned chips are mounted on a surface of a substrate via bump electrodes. In particular, there is a tendency that electronic chips such as IC and LSI chips are mounted on the surface of electronic parts via bump electrodes as flip chips without being packaged.
In order to conduct such surface mounting of such electronic parts, it is considered to be preferable that bump electrodes be formed on the side of such electronic parts.
Conventionally, the above-mentioned bump electrodes are formed on the surface of the above-mentioned electronic parts by an electrolytic plating method comprising the steps of forming a predetermined resist pattern on the surface of the electronic parts by photolithography, and having the resist pattern grown to a predetermined thickness, using solder, or a metal such as gold or copper, or by a ball bump method of forming metal balls from a metal wire, and bonding the metal balls to the electronic parts. These conventional methods are used as methods for directly forming bump electrodes on electronic parts. These methods, however, have a shortcoming that many steps to be carried out are involved and accordingly are costly to conduct.